diff --git a/developer/src/kmc/src/commands/build.ts b/developer/src/kmc/src/commands/build.ts
index bca00b74b9..60e91ddcfb 100644
--- a/developer/src/kmc/src/commands/build.ts
+++ b/developer/src/kmc/src/commands/build.ts
@@ -7,6 +7,7 @@ import { NodeCompilerCallbacks } from '../util/NodeCompilerCallbacks.js';
 import { InfrastructureMessages } from '../messages/messages.js';
 import { CompilerFileCallbacks, CompilerOptions, KeymanFileTypes } from '@keymanapp/common-types';
 import { BaseOptions } from '../util/baseOptions.js';
+import { expandFileLists } from '../util/fileLists.js';
 
 
 function commandOptionsToCompilerOptions(options: any): CompilerOptions {
@@ -29,7 +30,19 @@ function commandOptionsToCompilerOptions(options: any): CompilerOptions {
 export function declareBuild(program: Command) {
   BaseOptions.addAll(program
     .command('build [infile...]')
-    .description('Build a source file into a final file')
+    .description(`Compile one or more source files or projects.`)
+    .addHelpText('after', `
+Supported file types:
+  * folder: Keyman project in folder
+  * .kpj: Keyman project
+  * .kmn: Keyman keyboard
+  * .xml: LDML keyboard
+  * .model.ts: Keyman lexical model
+  * .kps: Keyman keyboard package
+
+File lists can be referenced with @filelist.txt.
+
+If no input file is supplied, kmc will build the current folder.`)
   )
     .option('-d, --debug', 'Include debug information in output')
     .option('-w, --compiler-warnings-as-errors', 'Causes warnings to fail the build; overrides project-level warnings-as-errors option')
@@ -48,10 +61,13 @@ export function declareBuild(program: Command) {
         filenames.push('.');
       }
 
+      if(!expandFileLists(filenames, callbacks)) {
+        process.exit(1);
+      }
+
       for(let filename of filenames) {
         if(!await build(filename, callbacks, options)) {
           // Once a file fails to build, we bail on subsequent builds
-          // TODO: is this the most appropriate semantics?
           process.exit(1);
         }
       }
diff --git a/developer/src/kmc/src/util/fileLists.ts b/developer/src/kmc/src/util/fileLists.ts
new file mode 100644
index 0000000000..11ce21905e
--- /dev/null
+++ b/developer/src/kmc/src/util/fileLists.ts
@@ -0,0 +1,49 @@
+import * as fs from 'fs';
+import * as path from 'path';
+import { CompilerCallbacks } from "@keymanapp/common-types";
+import { InfrastructureMessages } from "../messages/messages.js";
+
+/**
+ * Replaces each entry starting with `@` with the content of the file, with one
+ * line per file, filenames trimmed, and any lines that are blank or starting
+ * with `#` (marking a comment) removed. Note: `#` anywhere else is treated as
+ * part of the filename.
+ *
+ * If any filelist does not exist, reports an error and returns false.
+ *
+ * @param filenames
+ * @param callbacks
+ * @returns false on failure
+ */
+export function expandFileLists(filenames: string[], callbacks: CompilerCallbacks) {
+  let i = 0;
+  while(i < filenames.length) {
+    if(filenames[i].startsWith('@')) {
+      const fileList = expandFileList(filenames[i].substring(1), callbacks);
+      if(fileList === null) {
+        return false;
+      }
+      filenames.splice(i, 1, ...fileList);
+      i += fileList.length;
+    } else {
+      i++;
+    }
+  }
+  return true;
+}
+
+export function expandFileList(filename: string, callbacks: CompilerCallbacks): string[] {
+  if(!fs.existsSync(filename)) {
+    callbacks.reportMessage(InfrastructureMessages.Error_FileDoesNotExist({filename}));
+    return null;
+  }
+
+  const files = fs.readFileSync(filename, 'utf-8').split('\n').map(item => {
+    item = item.trim();
+    return item.startsWith('#') || item == ''
+      ? ''
+      : path.resolve(path.dirname(filename), item)
+  }).filter(item => item.length > 0);
+
+  return files;
+}
diff --git a/developer/src/kmc/test/fixtures/file-lists/files.txt b/developer/src/kmc/test/fixtures/file-lists/files.txt
new file mode 100644
index 0000000000..927f69c55e
--- /dev/null
+++ b/developer/src/kmc/test/fixtures/file-lists/files.txt
@@ -0,0 +1,15 @@
+
+#
+# This is a comment
+#
+
+file1.kmn
+
+  #
+  # we want to compile these files too
+  #
+
+  file2.kmn
+  file with space.kps
+
+# Some more commentary
diff --git a/developer/src/kmc/test/test-fileLists.ts b/developer/src/kmc/test/test-fileLists.ts
new file mode 100644
index 0000000000..5092ff849d
--- /dev/null
+++ b/developer/src/kmc/test/test-fileLists.ts
@@ -0,0 +1,61 @@
+import { TestCompilerCallbacks } from '@keymanapp/developer-test-helpers';
+import { assert } from 'chai';
+import 'mocha';
+import { makePathToFixture } from './helpers/index.js';
+import { expandFileList, expandFileLists } from '../src/util/fileLists.js';
+
+const callbacks = new TestCompilerCallbacks();
+
+// expandFileList expands each file name relative to the file list's supplied
+// filename, so we need to compare against the full path.
+const expectedFileList = [
+  makePathToFixture('file-lists', 'file1.kmn'),
+  makePathToFixture('file-lists', 'file2.kmn'),
+  makePathToFixture('file-lists', 'file with space.kps')
+];
+
+const expectedFiles = [
+  'file0.kmn',
+  ...expectedFileList,
+  'file4.kmn',
+  'file5.kmn'
+];
+
+beforeEach(function() {
+  callbacks.clear();
+});
+
+describe('expandFileList', function () {
+  it('should report a missing filelist correctly', async function() {
+    const path = makePathToFixture('file-lists', 'does-not-exist.txt');
+
+    const fileList = expandFileList(path, callbacks);
+    assert.isNull(fileList);
+    assert.equal(callbacks.messages.length, 1);
+  });
+
+  it('should expand a list of files correctly', async function() {
+    const path = makePathToFixture('file-lists', 'files.txt');
+
+    const fileList = expandFileList(path, callbacks);
+    assert.isNotNull(fileList);
+    assert.equal(callbacks.messages.length, 0);
+    assert.deepEqual(fileList, expectedFileList);
+  });
+});
+
+describe('expandFileLists', function () {
+  it('should splice a filelist in correctly', async function() {
+    // We just use this to test the splicing so no path resolution is made
+    const files = [
+      'file0.kmn',
+      '@' + makePathToFixture('file-lists', 'files.txt'),
+      'file4.kmn',
+      'file5.kmn'
+    ];
+
+    assert.isTrue(expandFileLists(files, callbacks));
+    assert.equal(callbacks.messages.length, 0);
+    assert.deepEqual(files, expectedFiles);
+  });
+});